Microchannel reactors may be used in a variety of catalytic processes wherein reactants contact a catalyst within the microchannel reactor and undergo reaction. These reactors have been shown to provide excellent performance and attractive economics for steam methane reforming (SMR) reactions at very short contact times using a catalyst coated on the interior walls of the microchannel reactor. However, reactions with longer contact times have in the past required either an engineered catalyst (e.g., a catalyst supported on a foam, felt, wad or fin) or a packed bed to increase the surface area for supporting the catalyst.
These approaches may result in one or more of a number of problems. These problems may include the fact that some engineered catalysts and packed beds tend to have relatively low effective thermal conductivities in the structure as well as in the interface between the structure and any adjacent heat transfer wall. Integration of a catalyst structure within a microchannel reactor after bonding may result in poor thermal contact with heat transfer walls. Pressure drop within the microchannel reactor may be relatively high when flow is predominately directed through the pores of the structure rather than by or past the structure. The use of reduced amounts of catalyst may equate to longer contact times.
This invention, in at least one embodiment, provides a solution to one or more of these problems.